Architects want to build a mile-high skyscraper in the Japanese city of Tokyo, two times the size of the world’s current tallest building. The aptly titled “Sky Mile Tower” is proposed as part of sustainable Tokyo development plan till 2045.

The tower would measure 5,577 feet (1,700 meters) in height, roughly double the size of Dubai’s Burj Khalifa, which comes in at 2,722 feet (830 meters).

To tackle the issue of pumping water around such a tall building, engineers have incorporated tanks at various points in the structure’s design which would collect, treat and store water, “while relying on gravity for a natural distribution.”

The super tower will be surrounded by a number of man-made hexagonal-shaped islands that form part of the development’s defense against natural disasters such as flooding and earthquakes, as well as being able to house half a million people.